Establishment of system for genomic mutation analysis using tissue stem cell in intestinal tumor

• Project/Area Number: 19H04268
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 63020:Radiation influence-related
• Research Institution: Osaka University
• Principal Investigator: Ishikawa-Fujiwara Tomoko 大阪大学, 放射線科学基盤機構附属ラジオアイソトープ総合センター, 特任研究員(常勤) (70402922)
• Co-Investigator(Kenkyū-buntansha): 辻村 亨 兵庫医科大学, 医学部, 教授 (20227408)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Project Status: Completed (Fiscal Year 2021)
• Budget Amount: ¥17,160,000 (Direct Cost: ¥13,200,000、Indirect Cost: ¥3,960,000); Fiscal Year 2021: ¥5,720,000 (Direct Cost: ¥4,400,000、Indirect Cost: ¥1,320,000); Fiscal Year 2020: ¥5,460,000 (Direct Cost: ¥4,200,000、Indirect Cost: ¥1,260,000); Fiscal Year 2019: ¥5,980,000 (Direct Cost: ¥4,600,000、Indirect Cost: ¥1,380,000)
• Keywords: 損傷乗り越えDNA合成 / 遺伝的不安定性 / 発がん / ミスマッチ修復 / Structure Variant (SV) / 二重鎖切断(DSB) / 点突然変異 / CNA / SNP / 次世代シーケンス / がん発症メカニズム / ゲノム不安定性 / メダカ / Rev3L / 自然発がん / モザイク解析 / 自然高発がん

Outline of Research at the Start

発がんは環境変異原による生物影響のエンドポイントであり、遺伝子変異はその最重要要因である。がん細胞については莫大な量のゲノム変異情報が得られているものの、遺伝子変異と発がん過程進行との相関は不明な点が多い。我々は、年齢依存的に大腸がんを必発するメダカ変異体を樹立した。本高発がん系を用い、化学発癌剤や放射線等の環境要因によるDNA損傷が大腸がん発症に与える影響、損傷応答や突然変異導入に関与する遺伝子の欠損の影響を、ゲノム変異同定することによりその一端を明らかにしたい。

Outline of Final Research Achievements

We have been trying to establish a spontaneous tumorigenesis model system that can analyze the correlation between genome mutations and tumorigenesis in detail. We have already found intestinal tumor prone rev3 deficient medaka mutant. In this study we found expression of several tumor-related genes were up- or down-regulated in tumor cells derived from abdominal cavity of the rev3 mutant using RNA-Seq. We generated double mutants with rev3 for other TLS polymerases (polh, polk, poli) which suppress induction of genome structure variants (SVs), for msh2 which is involved in nucleotide level mutations, and for atm which is involved in regulation of double strand break repair and subsequent chromosomal level rearrangements. In all case, the life span was shortened additionally in double mutant compared to each single mutant. These results suggest that induction of point mutations and SVs have additive effects on tumorigenesis, and that DSB repair has suppressive effect on SV induction.

Academic Significance and Societal Importance of the Research Achievements

がんは我が国でも死因の上位に占める疾患で、突然変異誘発が「発がん」の有力要因である事は明らかである。本研究では大腸がんを自然発症するメダカにおいて、がん細胞では哺乳類同様がん関連遺伝子の発現の上昇、低下が観察され、他の、突然変異を誘発する遺伝子との二重変異体では表現型が亢進することが示された。このように遺伝子変異と発がん過程進行がリアルタイムにモニタリングできる実験モデル動物系の開発により発がんのイニシエーションからプロモーションの変遷における遺伝子変異の役割解明か可能となると考えられる。今後、本系の完成により当該分野のみならず、広く生物・医学分野で極めて大きな役割を果たすと考えられる。

Research Products

• [Journal Article] 3D reconstructed brain images reveal the possibility of the ogg1 gene to suppress the irradiation-induced apoptosis in embryonic brain in medaka (Oryzias latipes) (2022)
  • Author(s): Takako Yasuda, Duolin Li, Erge Sha, Fumitaka Kakimoto, Hiroshi Mitani, Hiroshi Yamamoto, Tomoko Ishikawa-Fujiwara, Takeshi Todo, Shoji Oda
  • Journal Title: JOURNAL OF RADIATION RESEARCH Volume: - Issue: 3 Pages: 1-12
  • DOI: 10.1093/jrr/rrac005
  • Peer Reviewed / Open Access
• [Journal Article] Estrogen receptor 2b is the major determinant of sex-typical mating behavior and sexual preference in medaka (2021)
  • Author(s): Nishiike Yuji、Miyazoe Daichi、Togawa Rie、Yokoyama Keiko、Nakasone Kiyoshi、Miyata Masayoshi、Kikuchi Yukiko、Kamei Yasuhiro、Todo Takeshi、Ishikawa-Fujiwara Tomoko、Ohno Kaoru、Usami Takeshi、Nagahama Yoshitaka、Okubo Kataaki
  • Journal Title: Current Biology Volume: 31 Issue: 8 Pages: 1-12
  • DOI: 10.1016/j.cub.2021.01.089
  • Peer Reviewed / Open Access
• [Journal Article] Involvement of Rev1 in alkylating agent-induced loss of heterozygosity in Oryzias latipes. (2020)
  • Author(s): Fujikawa Y, Ishikawa-Fujiwara T, Kuo T, Shinkai N, Shoji T, Kawasaki T, Kamei Y, Sakuraba Y, Sato A, Kinoshita M, Gondo Y, Yuba S, Tsujimura T, Sese J, Todo T
  • Journal Title: Genes to Cells Volume: 25 Issue: 2 Pages: 124-138
  • DOI: 10.1111/gtc.12746
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] Genome instability of tumor prone rev3l deficient medaka mutant (2021)
  • Author(s): Tomoko Ishikawa-Fujiwara, Yoshihiro Fujikawa, Andres Canela, Tatsuma Shoji, Fei Sun, Jun Sese, Takeshi Todo
  • Organizer: 日本放射線影響学会第64回大会
• [Presentation] Genome analysis of Rev3l deficient medaka mutant (2020)
  • Author(s): Tomoko (Ishikawa) Fujiwara, Yoshihiro Fujikawa, Andres Canela, Tatsuma Shoji, Fei Sun, Jun Sese, Takeshi Todo
  • Organizer: 日本放射線影響学会第63回大会
• [Presentation] Characteristic feature of genomic instability in rev1 and rev3 mutants (2019)
  • Author(s): Tomoko Ishikawa-Fujiwara, Yoshihiro Fujikawa, Takeshi Todo
  • Organizer: 16th International Congress of Radiation Research
  • Int'l Joint Research
• [Presentation] A unique phenotype of medaka rev3l mutant (2019)
  • Author(s): Yoshihiro Fujikawa, Tomoko Ishikawa-Fujiwara, Ayuko Sato, Tetsushi Sakuma,Tsutomu Shimura, Takashi Yamamoto, Seiji Kodama, Tohru Tsujimura, Takeshi Todo
  • Organizer: 16th International Congress of Radiation Research
  • Int'l Joint Research
• [Presentation] Involvement of Trans Lesion Synthesis DNA polymerase on maintenance of Genome stability (2019)
  • Author(s): Tomoko Fujiwara, Yoshihiro Fujikawa, Takeshi Todo
  • Organizer: 日本放射線影響学会第62回大会
  • Invited
• [Presentation] Rev3l-deficent medaka provides an excellent model for studies of intestinal tumor development (2019)
  • Author(s): Yoshihiro Fujikawa, Tomoko Fujiwara, Ayuko Sato, Tsutomu Shimura, Seiji Kodama, Tohru Tsujimura, Takeshi Todo
  • Organizer: 日本放射線影響学会第62回大会
• [Presentation] 消化管腫瘍を高頻度に発がんするメダカrev3L変異体を用いた発がんメカニズムの解析 (2019)
  • Author(s): 藤川 芳宏 、藤原 智子 、佐藤 鮎子 、志村 勉 、 児玉 靖司 、辻村 亨 、藤堂 剛
  • Organizer: 第6回アジア環境変異原学会日本環境変異原学会第48回大会合同大会